Amadeus Mozart

Since both Amadeus and Nannerl showed musical ability, the father gave up his career and devoted himself to the children's musical education.

An excerpt from the article 28 facts about Amadeus Mozart

Amadeus learned to play the harpsichord from the age of five (even as a three-year-old, he listened to his sister play the instrument and toyed with finding thirds - this is how Maria Anna recalled it years later). Reportedly, even then he was making up his first minuets, which his father wrote down for him since he could not yet write himself, and at the age of eight, he composed his first symphony.